1. Field of the Invention
The present invention relates to a circuit to limit surges into a dc-operated lamp, for example, initial switch-on surge and arc discharge current.
2. Description of the Prior Art
Conventional starter circuits are effective in limitation of initial switch-on surge into lamp, but ineffective in limitation of an arc that may arise on burnout of filament. The arc discharges in a short-circuit manner, and continuously flows a surge of 200 amperes when, for example, a 60 watt lamp is operated with dc 130 volts. The surge may cause serious damage to circuit elements such as a rectifier and switching means.